1. Field of the Invention
The present invention relates to an apparatus for inspecting a laminated iron core formed by laminating a plurality of iron core pieces with predetermined shapes, and a method for inspecting the laminated iron core.
2. Description of the Related Art
In a laminated iron core, for example, as described in Japanese Patent No. 5094086 referred to as Patent Reference 1, a thin metal sheet is sequentially fed to a die unit, and a shaft hole of the center of the thin metal sheet is blanked and then, a slot for forming a magnetic pole piece is blanked. A caulking part for joining vertically adjacent iron core pieces is formed, and these iron core pieces are blanked off and are laminated inside a die to thereby manufacture the laminated iron core. Thereafter, the following inspections (quality inspections) of the presence or absence of defects in quality are conducted, and the laminated iron core is shipped. The inspections are as follows: (1) a positional displacement of the blanked iron core piece due to a mistake in feeding of the thin metal sheet, (2) a bite of a foreign substance at the time of laminating the iron core pieces, and (3) a stack displacement of unit laminated iron cores in the case of welding the plural stacked unit laminated iron cores formed by laminating the plural iron core pieces.
In the quality inspections described above, for example, an image inspecting apparatus 90 shown in FIGS. 6A and 6B is used. This image inspecting apparatus 90 includes a placement table 92 on which a laminated iron core 91 is placed, and two image cameras 93 for detecting a defect in quality.
In the case of using the image inspecting apparatus 90, after the two image cameras 93 are arranged over the laminated iron cores 91 so that each of the image cameras 93 overlaps with the laminated iron core 91 placed on the placement table 92 in plan view, the laminated iron ore 91 or the image camera 93 is rotated around the shaft center of the laminated iron core 91.
Patent Reference 1: Japanese Patent No. 5094086